1. Field of the Invention
The invention relates to a connector for circuit board and to a method of assembling it.
2. Description of the Related Art
U.S. Pat. No. 5,980,328 and FIG. 6 show two different connectors for circuit boards. The connector of FIG. 6 is identified by the numeral 1, and has terminal fittings 2 disposed in cavities 3 of a housing 4. The connector 1 also includes an alignment plate 5 for aligning the terminal fittings 2. Each terminal fitting 2 has a box 2A to be connected with a mating terminal fitting and a board connecting portion 2B to be connected with a circuit board P. A coupling portion 2C couples the box 2A and the board connecting portion 2B. Each cavity 3 has an open forward end and a terminal insertion hole 3A that opens widely at the rear side of the cavity 3. The box 2A of each terminal fitting 2 is inserted into the cavity 3 through the terminal insertion hole 3A and a lock 6 formed in the cavity 3 locks the box 2A. A similar arrangement is shown in U.S. Pat. No. 5,980,328. The coupling portion 2C of each terminal fitting 2 in FIG. 6 is bent down at right angles behind the cavity 3. The board connecting portions 2B of the terminal fittings 2 are introduced through positioning holes 5A in the alignment plate 5 and the alignment plate 5 is mounted at a rear bottom portion of the housing 4. The board connecting portions 2B of the terminal fittings 2 are introduced through holes in the circuit board P and are connected with circuits on the circuit board P by soldering to fix the housing 4 on the circuit board P. A similar board mounting is achieved for the connector shown in U.S. Pat. No. 5,980,328.
The terminal fittings 2 are likely to shake because the rear sides of the cavities 3 are large. Thus, it is difficult to align the board connecting portions 2B precisely, and assembling time may be longer. Similar problems occur with the connector shown in U.S. Pat. No. 5,980,328.
The invention was developed in view of the above problem and an object is to improve the operability of mounting a connector for circuit board.
The invention relates to a connector with a housing that can be fixed to the circuit board. The housing has opposite front and rear ends and cavities that extend between the ends. Each cavity has a terminal insertion hole at the front end of the housing for receiving a terminal fitting. Each terminal fitting has a box at one end configured for connection with a mating terminal fitting. A board connecting portion is at the opposite end of the terminal fitting and is configured for connection with the circuit board. A coupling portion couples the box and the board connecting portion. The box of each terminal fitting is accommodated in the corresponding cavity and the board connecting portion extends back from the cavity. A front holder is mounted onto the front end of the housing for holding the box of the terminal fitting in the cavity. Shake preventing holes are formed at the rear ends of the cavities and hold the coupling portions without shaking.
Accordingly, terminal fittings can be inserted into the cavities through the terminal insertion holes at the front ends of the cavities by holding the box and inserting the board connecting portion first. The front holder then is mounted onto the front end of the housing to prevent the terminal fittings from coming out. The coupling portions of the terminal fittings are positioned by the shake preventing holes at the rear ends of the cavities to prevent the terminal fittings from shaking. Thus, the board connecting portions of the terminal fittings can be aligned with improved precision and the connector can be assembled more smoothly.
The shake preventing holes preferably have a smaller vertical dimension than the terminal insertion holes.
The terminal fittings preferably are constructed such that the coupling portions are bendable in or behind the cavities. Additionally, positioning walls may be formed in the cavities for contacting the rear ends of the boxes and positioning the terminal fittings longitudinally. In contrast, it had been difficult to position terminal fittings accurately in prior art terminal fittings due to a dimensional difference between the terminal fittings and the locks. Thus, there had been a variation in positions where the terminal fittings were bent and precise alignment was difficult. However, the terminal fittings of the subject invention can be bent at precise positions by bending while the box is pressed against the positioning walls. As a result, alignment precision is improved.
The boxes of the terminal fittings preferably are held between the front holder and the positioning walls.
The housing is made of a hard synthetic resin and may contain glass. Resilient members, such as locks, are difficult to form using the hard synthetic resin containing glass. Therefore, it has been difficult to make the prior art housing of a hard synthetic resin. However, it is not necessary to provide locks in the housing of the subject connector. Accordingly the housing can be made of a hard synthetic resin containing glass and has a higher strength.
The invention also relates to a method of assembling a connector for circuit board. The connector includes terminal fittings, each of which has a box to be connected with a mating terminal fitting, a board connecting portion to be connected with a circuit board and a coupling portion coupling the box portion and the board connecting portion. The method comprises providing a housing formed with cavities which are open forward and backward. The method then includes inserting the terminal fittings, board connecting portion first, into the front ends of the cavities, and accommodating the boxes of the terminal fittings in the cavities. Thus, the board connecting portions extend back from the cavities. The method then includes mounting a front holder onto the front of the housing to prevent the terminal fittings from coming out.
The terminal fitting can be inserted into the cavity from the front through terminal insertion holes. Thus, it is possible to manipulate the terminal fittings by the box, which is larger and stronger than the board connecting portion.
The step of inserting the terminal fitting preferably comprises inserting the coupling portions through shake preventing holes at the rear of the housing.
The method may further comprise fixing the housing to the circuit board.
The method may also comprise bending the coupling portions in or behind the cavities.
The step of inserting the terminal fittings may comprise urging the boxes into contact with positioning walls for positioning the terminal fittings with respect to forward and backward directions.
These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments.